function f = ppq(x)
%Partial Perturbed Quadratic Function   
%x0=[0.5, 0.5, ..., 0.5]...  
%fmin=n/2,m=20
%Author:shi yangyang
n=length(x);
temp(1)=x(1)+x(2);
for i=2:n-1
    temp(i)=temp(i-1)+x(i+1);
end              
f=x(1)*x(1);
for i=2:n
    f=f+(i)*x(i)*x(i)+temp(i-1)*temp(i-1)/100.0;
end 
% f;
